Assemblies of this type are described, for example, in U.S. Pat. Nos. 2,627,120 and 3,806,214. The bearings shown in these prior patents have inner and outer raceways formed by respective bearing rings or sleeves each split into two mutually symmetrical, generally cup-shaped halves to facilitate their emplacement. With a so-called "O" mounting (see also commonly owned U.S. Pat. No. 4,089,570 ), each set of rotary bodies engages respective halves of the two bearing rings along axially offset contact zones so as to define two sets of seat axes which converge in a radially outward direction; with an "X" mounting these seat axes converge toward the shaft axis. The "O" mounting exerts an axial thrust upon the two halves of the outer bearing ring in a sense urging them toward each other. This thrust can be utilized, as described in the two first-mentioned prior patents, to clamp an annular housing flange between the two outer ring halves for holding the assembly in position.
The presence of such a housing flange, which must have a certain axial width in order to exhibit the necessary structural strength, requires a corresponding separation of the halves of the outer bearing ring so as to increase the overall axial extent of the bearing if the width of the outer raceways is to be maintained. For the sake of stability, moreover, the housing member carrying the flange must be axially enlarged on both sides thereof to form a radial abutment for the halves of the outer bearing ring.